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Tube Notching

I have used a few different methods to notch tube over the years. Some that work great and are worth the time to set up others not so much. Today I needed to notch a 40mm diametre tube to fit to a 100mm diametre tube at 90 degrees. I noticed this free download program that has been around a while and thought I would give it a go "Tubemitre". I punched in the data and printed out the result. Used sticky tape to fix the paper template to the tube and with the aid of an air hacksaw cut away the excess in a few minutes. The result without any sanding is just about good enough to start welding.
Pretty cool.

Works in a pinch but if you do any real work you need to have a means of just setting a degree and go. Pretty cool using the math though. I did my first fish mouths with a similar program close to ten years ago, thought it was the bees knees till I used a hole saw based jig, then even better a nibbler style, and now I use the mill. Just gets more accurate and faster.

How much did a bit cost that would notch a 100mm or 4" bite out of a 40mm tube?
How long does it take from start to finish?
The tubemitre system with a air hacksaw took about 6 minutes total.
At a cost of $150 because the hacksaw was a Snap On Bluepoint.
The room taken up in my workshop is very little.
As I said this is petty good for what is required to get a really good fit up.

I only have to notch a few pipes every once in a while. I paid $300 for a P & N hole saw set to use for the job on my drill press. Problem with this is that the hole saws don't match tube diameters which means to get a good fit up you have to file or sand. Also the largest hole saw in the set is 75mm or 3" diameter which means more work after the cut is made to make a good fit up for this project. I could use a linisher with tube diameter spindles and a cross slide table to feed the tube into the grinding belt but they cost $2500 and take up half a car space in the workshop. I could pay $25000 and get a CNC mill or $250 000 and get a CNC laser which would take up the size of a car in the workshop. These certainly would speed up the notching but for the few times a year I have to do this the best bang for my buck is this program and an air saw. It will do any diameter tube at any angle with the least waste, takes up no space in my workshop and costs nothing. If you are doing tube work all the time yep this is way to slow, I agree. But then you would have one of those alternatives and a operator that just notches tube, or have the work outsourced by a laser cutting company.